001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.processor; 018 019import org.apache.camel.Exchange; 020 021/** 022 * An advice (before and after) to execute cross cutting functionality in the Camel routing engine. 023 * <p/> 024 * The Camel routing engine will execute the {@link #before(org.apache.camel.Exchange)} and 025 * {@link #after(org.apache.camel.Exchange, Object)} methods during routing in correct order. 026 * 027 * @param <T> 028 * @see CamelInternalProcessor 029 */ 030public interface CamelInternalProcessorAdvice<T> { 031 032 /** 033 * Callback executed before processing a step in the route. 034 * 035 * @param exchange the current exchange 036 * @return any state to keep and provide as data to the {@link #after(org.apache.camel.Exchange, Object)} method, or use <tt>null</tt> for no state. 037 * @throws Exception is thrown if error during the call. 038 */ 039 T before(Exchange exchange) throws Exception; 040 041 /** 042 * Callback executed after processing a step in the route. 043 * 044 * @param exchange the current exchange 045 * @param data the state, if any, returned in the {@link #before(org.apache.camel.Exchange)} method. 046 * @throws Exception is thrown if error during the call. 047 */ 048 void after(Exchange exchange, T data) throws Exception; 049}